What unites the nervous and endocrine systems. Nervous and endocrine systems. central nervous system

The human body consists of cells that combine into tissues and systems - all this as a whole is a single super-system of the body. The myriads of cellular elements would not be able to work as a whole if the body did not have a complex regulation mechanism. The nervous system and the endocrine gland system play a special role in regulation. The nature of the processes occurring in the central nervous system is largely determined by the state of endocrine regulation. So androgens and estrogens form the sexual instinct, many behavioral reactions. It is obvious that neurons, just like other cells in our body, are under the control of the humoral regulatory system. The nervous system, evolutionarily later, has both governing and subordinate connections with the endocrine system. These two regulatory systems complement each other, form a functionally single mechanism, which ensures high efficiency of neurohumoral regulation, puts it at the head of the systems that coordinate all vital processes in a multicellular organism. The regulation of the constancy of the internal environment of the body, taking place according to the principle of feedback, is very effective for maintaining homeostasis, but it cannot fulfill all the tasks of adaptation of the body. For example, the adrenal cortex produces steroid hormones in response to hunger, illness, emotional arousal, etc. In order for the endocrine system to “respond” to light, sounds, smells, emotions, etc., there must be a connection between the endocrine glands and the nervous system ...

1.1 Brief description of the system

The autonomic nervous system permeates our entire body like the thinnest spider web. It has two branches: excitation and inhibition. The sympathetic nervous system is the excitatory part, it puts us in a state of readiness to face a challenge or danger. Nerve endings secrete mediators that stimulate the adrenal glands to release strong hormones - adrenaline and norepinephrine. They in turn increase the heart rate and respiration rate, and act on the digestive process by secreting acid in the stomach. In this case, there is a sucking sensation in the stomach. Parasympathetic nerve endings secrete other neurotransmitters that lower the heart rate and respiratory rate. Parasympathetic responses are relaxation and rebalancing.

The endocrine system of the human body combines small in size and different in structure and function of the endocrine glands, which are part of the endocrine system. These are the pituitary gland with its independently functioning anterior and posterior lobes, the gonads, the thyroid and parathyroid glands, the adrenal cortex and medulla, the islet cells of the pancreas and the secretory cells lining the intestinal tract. All together they weigh no more than 100 grams, and the amount of hormones they produce can be calculated in billions of a gram. And, nevertheless, the sphere of influence of hormones is extremely large. They have a direct impact on the growth and development of the body, on all types of metabolism, on puberty. There are no direct anatomical connections between the endocrine glands, but there is an interdependence of the functions of one gland on the others. The endocrine system of a healthy person can be compared to a well-played orchestra, in which each gland confidently and subtly leads its part. And in the role of the conductor is the main supreme endocrine gland - the pituitary gland. The anterior pituitary gland releases six tropic hormones into the blood: somatotropic, adrenocorticotropic, thyroid-stimulating, prolactin, follicle-stimulating and luteinizing - they direct and regulate the activity of other endocrine glands.

1.2 Interaction of the endocrine and nervous system

The pituitary gland can receive signals that signal what is happening in the body, but it has no direct connection with the external environment. Meanwhile, in order for the factors of the external environment not to constantly disturb the vital activity of the organism, the body must adapt to the changing external conditions. The body learns about external influences through the senses, which transmit the information received to the central nervous system. As the supreme gland of the endocrine system, the pituitary gland itself obeys the central nervous system and, in particular, the hypothalamus. This higher vegetative center constantly coordinates, regulates the activity of various parts of the brain, all internal organs. Heart rate, blood vessel tone, body temperature, the amount of water in the blood and tissues, the accumulation or consumption of proteins, fats, carbohydrates, mineral salts - in short, the existence of our body, the constancy of its internal environment is controlled by the hypothalamus. Most of the nervous and humoral pathways of regulation converge at the level of the hypothalamus, and due to this, a single neuroendocrine regulatory system is formed in the body. Axons of neurons located in the cerebral cortex and subcortical formations are suitable for the cells of the hypothalamus. These axons secrete various neurotransmitters that have both activating and inhibitory effects on the secretory activity of the hypothalamus. The hypothalamus "converts" the nerve impulses coming from the brain into endocrine stimuli, which can be strengthened or weakened depending on the humoral signals entering the hypothalamus from the glands and tissues subordinate to it.

and is enriched there with hypothalamic neurohormones. Neurohormones are peptide substances, which are parts of protein molecules. To date, seven neurohormones have been discovered, the so-called liberins (that is, liberators), which stimulate the synthesis of tropic hormones in the pituitary gland. And three neurohormones - prolactostatin, melanostatin and somatostatin, on the contrary, inhibit their production. Neurohormones also include vasopressin and oxytocin. Oxytocin stimulates the contraction of the smooth muscles of the uterus during childbirth, the production of milk by the mammary glands. Vasopressin is actively involved in the regulation of the transport of water and salts through cell membranes; under its influence, the lumen of blood vessels decreases and, therefore, blood pressure increases. Because this hormone has the ability to retain water in the body, it is often called antidiuretic hormone (ADH). The main point of ADH application is the renal tubules, where it stimulates the reabsorption of water from the primary urine into the blood. Nerve cells of the hypothalamic nuclei produce neurohormones, and then transport them to the posterior lobe of the pituitary gland along their own axons (nerve processes), and from here these hormones enter the bloodstream, exerting a complex effect on the body systems.

processes of cell differentiation, increases the sensitivity of the gonads to gonadotropins, stimulates the parental instinct. Corticotropin is not only a stimulant of sterogenesis, but also an activator of lipolysis in adipose tissue, as well as an important participant in the process of converting short-term memory into long-term memory in the brain. Growth hormone can stimulate the activity of the immune system, the metabolism of lipids, sugars, etc. Also, some hormones of the hypothalamus and pituitary gland can be formed not only in these tissues. For example, somatostatin (a hypothalamic hormone that inhibits the production and secretion of growth hormone) is also found in the pancreas, where it inhibits the secretion of insulin and glucagon. Some substances work in both systems; they can be hormones (i.e., products of the endocrine glands) and mediators (products of certain neurons). This dual role is played by norepinephrine, somatostatin, vasopressin and oxytocin, as well as diffuse gut nervous system transmitters such as cholecystokinin and vasoactive intestinal polypeptide.

However, one should not think that the hypothalamus and pituitary gland only give orders, releasing the "leading" hormones along the chain. They themselves sensitively analyze the signals coming from the periphery, from the endocrine glands. The activity of the endocrine system is carried out on the basis of a universal feedback principle. An excess of hormones of a particular endocrine gland inhibits the release of a specific hormone from the pituitary gland, which is responsible for the work of this gland, and a deficiency prompts the pituitary gland to increase the production of the corresponding triple hormone. The mechanism of interaction between the neurohormones of the hypothalamus, the triple hormones of the pituitary gland and the hormones of the peripheral endocrine glands in a healthy organism has been worked out by long evolutionary development and is very reliable. However, a failure in one link of this complex chain is enough for a violation of quantitative and sometimes qualitative relationships in the whole system to occur, entailing various endocrine diseases.

CHAPTER 2. BASIC TALAMUS FUNCTIONS

2.1 Brief Anatomy

The bulk of the diencephalon (20 g) is the thalamus. The paired organ is ovoid, the anterior part of which is pointed (anterior tubercle), and the posterior expanded one (pillow) hangs over the geniculate bodies. The left and right thalamuses are connected by an interthalamic adhesion. The gray matter of the thalamus is divided by plates of white matter into anterior, medial, and lateral parts. Speaking of the thalamus, they also include the metathalamus (geniculate bodies), which belongs to the thalamic region. The thalamus is most developed in humans. Thalamus (thalamus), the visual hillock, is a nuclear complex in which processing and integration of almost all signals going to the cerebral cortex from the spinal cord, midbrain, cerebellum, basal ganglia of the brain takes place.

ganglia of the brain. In the nuclei of the thalamus, information is switched from extero-, proprioceptors and interoreceptors, and thalamocortical pathways begin. Considering that the geniculate bodies are the subcortical centers of vision and hearing, and the frenum node and the anterior visual nucleus are involved in the analysis of olfactory signals, it can be argued that the visual hillock as a whole is a subcortical "station" for all types of sensitivity. Here irritations of the external and internal environment are integrated, after which they enter the cerebral cortex.

The visual hillock is the center of the organization and realization of instincts, drives, emotions. The ability to obtain information about the state of many body systems allows the thalamus to participate in the regulation and determination of the functional state of the body. In general (this is confirmed by the presence of about 120 differently functional nuclei in the thalamus).

2.3 Functions of thalamic nuclei

share of the bark. Lateral - in the parietal, temporal, occipital lobes of the cortex. The thalamic nuclei are functionally divided into specific, non-specific and associative pathways by the nature of the pathways entering and leaving them.

2.1 Specific sensory and non-sensory nuclei

Specific nuclei include the anterior ventral, medial, ventrolateral, postlateral, postmedial, lateral and medial geniculate bodies. The latter belong to the subcortical centers of vision and hearing, respectively. The main functional units of specific thalamic nuclei are "relay" neurons, which have few dendrites and a long axon; their function is to switch information going to the cerebral cortex from skin, muscle and other receptors.

In turn, specific (relay) cores are divided into sensory and non-sensory. From specific sensory nuclei, information about the nature of sensory stimuli enters strictly defined areas of the III-IV layers of the cerebral cortex. Dysfunction of specific nuclei leads to the loss of specific types of sensitivity, since the thalamic nuclei, like the cerebral cortex, have somatotopic localization. Individual neurons of specific thalamic nuclei are excited by receptors of their own type only. Signals from receptors in the skin, eyes, ear, and muscular system go to specific nuclei of the thalamus. Signals from the interoreceptors of the projection zones of the vagus and celiac nerves and the hypothalamus also converge here. The lateral geniculate body has direct efferent connections with the occipital lobe of the cerebral cortex and afferent connections with the retina and with the anterior tubercles of the quadruples. The neurons of the lateral geniculate bodies react differently to color stimuli, turning on and off light, i.e., they can perform a detector function. The medial geniculate body receives afferent impulses from the lateral loop and from the lower tubercles of the quadruples. The efferent pathways from the medial geniculate bodies go to the temporal zone of the cerebral cortex, reaching there the primary auditory cortex.

nuclei are projected into the limbic cortex, from where axonal connections go to the hippocampus and again to the hypothalamus, as a result of which a neural circle is formed, the movement of excitation along which provides the formation of emotions ("Peipets emotional ring"). In this regard, the anterior nuclei of the thalamus are considered as part of the limbic system. The ventral nuclei are involved in the regulation of movement, thus performing a motor function. In these nuclei, impulses are switched from the basal ganglia, the dentate nucleus of the cerebellum, the red nucleus of the midbrain, which is then projected into the motor and premotor cortex. Through these nuclei of the thalamus, complex motor programs formed in the cerebellum and basal ganglia are transmitted to the motor cortex.

2.2.3.2 Nonspecific nuclei

neurons are also functionally regarded as a derivative of the reticular formation of the brainstem. The neurons of these nuclei form their connections according to the reticular type. Their axons rise into the cerebral cortex and come into contact with all its layers, forming diffuse connections. Connections from the reticular formation of the brainstem, hypothalamus, limbic system, basal ganglia, specific nuclei of the thalamus come to the nonspecific nuclei. Thanks to these connections, the nonspecific nuclei of the thalamus act as an intermediary between the brain stem and the cerebellum, on the one hand, and the neocortex, limbic system, and basal ganglia, on the other hand, uniting them into a single functional complex.

2.3.3 Associative kernels

multipolar, bipolar three-process neurons, i.e. neurons capable of performing polysensory functions. A number of neurons change their activity only with simultaneous complex stimulation. Pillow phenomena), speech and visual functions (integration of the word with the visual image), as well as in the perception of the "body scheme". receives impulses from the hypothalamus, amygdala, hippocampus, thalamic nuclei, central gray matter of the trunk. The projection of this nucleus extends to the associative frontal and limbic cortex. It participates in the formation of emotional and behavioral motor activity. Lateral nuclei receive visual and auditory impulses from the geniculate bodies and somatosensory impulses from the ventral nucleus.

Motor reactions are integrated in the thalamus with the vegetative processes that provide these movements.

CHAPTER 3. COMPOSITION OF THE LIMBIC SYSTEM AND ITS PURPOSE

The structures of the limbic system include 3 complexes. The first complex is the ancient bark, olfactory bulbs, olfactory tubercle, transparent septum. The second complex of structures of the limbic system is the old cortex, which includes the hippocampus, dentate fascia, and cingulate gyrus. The third complex of the limbic system is the structure of the insular cortex, the parahippocampal gyrus. And subcortical structures: amygdala, nucleus of the transparent septum, anterior thalamic nucleus, mastoid bodies. The hippocampus and other structures of the limbic system are surrounded by the cingulate gyrus. A vault is located near it - a system of fibers running in both directions; it follows the curve of the cingulate gyrus and connects the hippocampus to the hypothalamus. All the numerous formations of the limbic cortex encircle the base of the forebrain in an annular fashion and are a kind of border between the neocortex and the brainstem.

3.2 Morphofunctional organization of the system

is a functional association of brain structures involved in the organization of emotional and motivational behavior, such as food, sexual, defensive instincts. This system is involved in organizing the wakefulness-sleep cycle.

circulating the same excitation in the system and thereby to maintain a single state in it and to impose this state on other brain systems. At present, the connections between the structures of the brain, organizing circles, which have their own functional specificity, are well known. These include the Peipets circle (hippocampus - mastoid bodies - anterior thalamic nuclei - cingulate cortex - parahippocampal gyrus - hippocampus). This circle has to do with memory and learning.

Another circle (amygdala - mammillary bodies of the hypothalamus - limbic region of the midbrain - amygdala) regulates aggressive-defensive, nutritional and sexual forms of behavior. It is believed that figurative (iconic) memory is formed by the cortico-limbic-thalamo-cortical circle. Circles of different functional purposes connect the limbic system with many structures of the central nervous system, which allows the latter to realize functions, the specificity of which is determined by the included additional structure. For example, the inclusion of the caudate nucleus in one of the circles of the limbic system determines its participation in the organization of inhibitory processes of higher nervous activity.

A large number of connections in the limbic system, a kind of circular interaction of its structures create favorable conditions for the reverberation of excitation in short and long circles. This, on the one hand, ensures the functional interaction of parts of the limbic system, on the other hand, it creates conditions for memorization.

3.3 Functions of the limbic system

The abundance of connections between the limbic system and the structures of the central nervous system makes it difficult to isolate brain functions in which it would not take part. So, the limbic system is related to the regulation of the level of reaction of the autonomous, somatic systems during emotional-motivational activity, regulation of the level of attention, perception, reproduction of emotionally significant information. The limbic system determines the choice and implementation of adaptive forms of behavior, the dynamics of congenital forms of behavior, maintenance of homeostasis, and generative processes. Finally, it provides the creation of an emotional background, the formation and implementation of the processes of higher nervous activity. It should be noted that the ancient and old cortex of the limbic system is directly related to the olfactory function. In turn, the olfactory analyzer, as the most ancient of the analyzers, is a nonspecific activator of all types of activity of the cerebral cortex. Some authors call the limbic system the visceral brain, that is, the structure of the central nervous system involved in the regulation of the activity of internal organs.

This function is carried out mainly through the activity of the hypothalamus, which is the diencephalic link of the limbic system. The close efferent connections of the system with internal organs are evidenced by a variety of changes in their functions when the limbic structures, especially the tonsils, are irritated. In this case, the effects have a different sign in the form of activation or inhibition of visceral functions. There is an increase or decrease in the heart rate, motility and secretion of the stomach and intestines, the secretion of various hormones by the adenohypophysis (adenocorticotropins and gonadotropins).

3.3.2 Formation of emotions

Emotions - these are experiences that reflect the subjective attitude of a person to the objects of the external world and the results of his own activity. In turn, emotions are a subjective component of motivations - states that trigger and implement behavior aimed at satisfying emerging needs. Through the mechanism of emotions, the limbic system improves the body's adaptation to changing environmental conditions. The hypothalamus is a critical area for emotions to arise. In the structure of emotions, emotional experiences proper and its peripheral (vegetative and somatic) manifestations are distinguished. These components of emotion can be relatively independent. Expressed subjective experiences may be accompanied by minor peripheral manifestations and vice versa. The hypothalamus is a structure primarily responsible for the vegetative expression of emotions. In addition to the hypothalamus, the cingulate gyrus and amygdala are among the structures of the limbic system most closely associated with emotions.

with the provision of defensive behavior, autonomic, motor, emotional reactions, motivation of conditioned reflex behavior. The tonsils react with many of their nuclei to visual, auditory, interoceptive, olfactory, skin irritations, and all these irritations cause a change in the activity of any of the nuclei of the amygdala, that is, the nuclei of the amygdala are polysensory. Irritation of the amygdala nuclei creates a pronounced parasympathetic effect on the activity of the cardiovascular and respiratory systems. It leads to a decrease (rarely to an increase) in blood pressure, a slowdown in the heart rate, a violation of the conduction of excitation through the conducting system of the heart, the occurrence of arrhythmias and extrasystoles. In this case, the vascular tone may not change. Irritation of the tonsil nuclei causes respiratory depression, sometimes a cough reaction. Conditions such as autism, depression, post-traumatic shock, and phobias are thought to be associated with abnormal functioning of the amygdala. The cingulate gyrus has numerous connections with the neocortex and with the brainstem centers. And it plays the role of the main integrator of various brain systems that form emotions. Its functions are to provide attention, sensation of pain, ascertaining errors, transmitting signals from the respiratory and cardiovascular systems. The ventral frontal cortex has pronounced connections with the amygdala. The defeat of the cortex causes sharp disturbances in human emotions, characterized by the emergence of emotional dullness and disinhibition of emotions associated with the satisfaction of biological needs.

3.3.3 Formation of memory and implementation of learning

This function is related to the main circle of Peipets. In one-time training, the amygdala plays an important role due to its ability to induce strong negative emotions, contributing to the rapid and lasting formation of a temporary connection. Among the structures of the limbic system responsible for memory and learning, the hippocampus and the associated posterior zones of the frontal cortex play an important role. Their activity is absolutely necessary for the consolidation of memory - the transition of short-term memory to long-term memory.

Neurons are the building blocks for the human "message system"; there are entire networks of neurons that transmit signals between the brain and body. These organized networks of more than a trillion neurons create what is called the nervous system. It consists of two parts: the central nervous system (brain and spinal cord) and peripheral (nerves and nerve networks throughout the body)

Endocrine systempart of the body communication system. Uses glands throughout the body that regulate many processes such as metabolism, digestion, blood pressure and growth. Among the most important endocrine glands are the pineal gland, hypothalamus, pituitary gland, thyroid gland, ovaries and testicles.

central nervous system(CNS) consists of the brain and spinal cord.

Peripheral nervous system(PNS) consists of nerves that extend beyond the central nervous system. The PNS can be further divided into two different nervous systems: somaticand vegetative.

Somatic nervous system: The somatic nervous system transmits physical sensations and commands to movements and actions.

Autonomic nervous system: The autonomic nervous system controls involuntary functions such as heart rate, breathing, digestion, and blood pressure. This system is also associated with emotional responses such as sweating and crying.

10. Lower and higher nervous activity.

Lower nervous activity (LND) -directed to the internal environment of the body. This is a set of neurophysiological processes that ensure the implementation of unconditioned reflexes and instincts. This is the activity of the Spinal Cord and the Brain Trunk, which ensures the regulation of the activity of internal organs and their relationship, due to which the body functions as a whole.

Higher nervous activity (VND) -aimed at the external environment. This is a set of neurophysiological processes that provide conscious and subconscious processing of information, assimilation of information, adaptive behavior to the environment and learning in ontogenesis of all types of activity, including purposeful behavior in society.

11. Physiology of adaptation and stress.

Adaptation syndrome:

The first is called the anxiety stage. This stage is associated with the mobilization of the body's defense mechanisms, an increase in the level of adrenaline in the blood.

The next stage is called the stage of resistance or resistance. This stage is distinguished by the highest level of body resistance to the action of harmful factors, which reflects the ability to maintain the state of homeostasis.

If the impact of the stressor continues, then, as a result, “adaptation energy”, i. the adaptive mechanisms involved in maintaining the stage of resistance will exhaust themselves. Then the organism enters the final stage - the stage of exhaustion, when the survival of the organism may be at risk.

The human body copes with stress in the following ways:

1. Stressors are analyzed in the higher regions of the cerebral cortex, after which certain signals are sent to the muscles responsible for movement, preparing the body to respond to the stressor.

2. The stressor also affects the autonomic nervous system. The pulse quickens, the pressure rises, the level of erythrocytes and blood sugar rises, breathing becomes frequent and intermittent. This increases the amount of oxygen entering the tissues. The person turns out to be ready to fight or flight.

3. From the analyzing parts of the cortex, signals enter the hypothalamus and adrenal glands. The adrenal glands regulate the release of adrenaline into the blood, which is a common fast-acting stimulant.

Last updated: 30/09/2013

Description of the structure and functions of the nervous and endocrine systems, the principle of operation, their significance and role in the body.

While these are the building blocks for the human "message system," there are entire networks of neurons that transmit signals between the brain and body. These organized networks of more than a trillion neurons create what is called the nervous system. It consists of two parts: the central nervous system (brain and spinal cord) and peripheral (nerves and nerve networks throughout the body)

The endocrine system is also an integral part of the body's information transmission system. This system uses glands throughout the body to regulate many processes such as metabolism, digestion, blood pressure, and growth. Although the endocrine system is not directly connected to the nervous system, they often work together.

central nervous system

The central nervous system (CNS) consists of the brain and spinal cord. The primary form of communication in the central nervous system is a neuron. The brain and spinal cord are vital to the functioning of the body, so there are a number of protective barriers around them: bones (skull and spine), and membrane tissues (meninges). In addition, both structures are located in the cerebrospinal fluid that protects them.

Why are the brain and spinal cord so important? One should think that these structures are the de facto center of our "message system". The central nervous system is able to process all of your sensations and reflect on the experience of these sensations. Information about pain, touch, cold, etc. is collected by receptors throughout the body, and then transmitted to the nervous system. The central nervous system also sends signals to the body in order to control movements, actions and reactions to the outside world.

Peripheral nervous system

The peripheral nervous system (PNS) consists of nerves that extend beyond the central nervous system. The nerves and neural networks of the PNS are really just bundles of axons that emerge from nerve cells. Nerves range in size from relatively small to large enough to be easily seen even without a magnifying glass.

The PNS can be further divided into two different nervous systems: somatic and vegetative.

Somatic nervous system: transfers physical sensations and commands to movements and actions. This system consists of afferent (sensory) neurons that deliver information from nerves to the brain and spinal cord, and efferent (sometimes some of them are called motor) neurons that transmit information from the central nervous system to muscle tissues.

Autonomic nervous system: controls involuntary functions such as heart rate, breathing, digestion, and blood pressure. This system is also associated with emotional responses such as sweating and crying. The autonomic nervous system can be further divided into sympathetic and parasympathetic systems.

Sympathetic nervous system: The sympathetic nervous system controls the body's responses to stress. When this system works, breathing and heart rate increase, digestion slows down or stops, pupils dilate and sweat increases. This system is responsible for preparing the body for a dangerous situation.

Parasympathetic nervous system: The parasympathetic nervous system acts in opposition to the sympathetic system. This system helps to “calm down” the body after a critical situation. Heartbeat and breathing slow down, digestion resumes, pupils constrict and sweating stops.

Endocrine system

As noted earlier, the endocrine system is not part of the nervous system, but is still required for the transmission of information through the body. This system consists of glands that secrete chemical messengers called hormones. They are transported through the blood to specific areas of the body, including organs and tissues of the body. Among the most important endocrine glands are the pineal gland, hypothalamus, pituitary gland, thyroid gland, ovaries and testicles. Each of these glands has specific functions in different areas of the body.

Bilateral action of the nervous and endocrine systems

Every tissue and organ of a person functions under dual control: the autonomic nervous system and humoral factors, in particular hormones. This double control is the basis for the "reliability" of regulatory influences, the task of which is to maintain a certain level of individual physical and chemical parameters of the internal environment.

These systems stimulate or inhibit various physiological functions in order to minimize deviations in these parameters despite significant fluctuations in the external environment. This activity is consistent with the activity of the systems that ensure the interaction of the organism with the conditions of the environment, which is constantly changing.

Human organs have a large number of receptors, the irritation of which causes various physiological reactions. At the same time, many nerve endings from the central nervous system approach the organs. This means that there is a two-way connection of human organs with the nervous system: they receive signals from the central nervous system and, in turn, are the source of reflexes that change the state of themselves and the body as a whole.

The endocrine glands and the hormones they produce are closely interconnected with the nervous system, forming a general integral regulatory mechanism.

The connection of the endocrine glands with the nervous system is bi-directional: the glands are tightly innervated by the autonomic nervous system, and the secretion of the glands through the blood acts on the nerve centers.

Remark 1

To maintain homeostasis and carry out basic life functions, two main systems have evolved evolutionarily: the nervous and the humoral, which work in concert.

Humoral regulation is carried out by the formation in the endocrine glands or groups of cells that perform an endocrine function (in the glands of mixed secretion), and the entry of biologically active substances - hormones into the circulating fluids. The hormones are characterized by a distant effect and the ability to influence at very low concentrations.

The integration of nervous and humoral regulation in the body is especially pronounced during the action of stress factors.

The cells of the human body are united into tissues, and those, in turn, into organ systems. In general, all this represents a single supersystem of the body. All a huge number of cellular elements in the absence of a complex regulatory mechanism in the body would not have the ability to function as a whole.

The endocrine glandular system and the nervous system play a special role in regulation. It is the state of endocrine regulation that determines the nature of all processes occurring in the nervous system.

Example 1

Under the influence of androgens and estrogens, instinctive behavior and sexual instincts are formed. It is obvious that the humoral system also controls neurons, as well as other cells in our body.

Evolutionarily, the nervous system arose later than the endocrine system. These two regulatory systems complement each other, forming a single functional mechanism that provides highly effective neurohumoral regulation, placing it at the head of all systems that coordinate all life processes of a multicellular organism.

This regulation of the constancy of the internal environment in the body, which occurs according to the principle of feedback, cannot fulfill all the tasks of adaptation of the body, but is very effective for maintaining homeostasis.

Example 2

The adrenal cortex produces steroid hormones in response to emotional arousal, illness, hunger, etc.

A connection is needed between the nervous system and the endocrine glands so that the endocrine system can respond to emotions, light, smells, sounds, etc.

Regulatory role of the hypothalamus

The regulating effect of the central nervous system on the physiological activity of the glands is carried out through the hypothalamus.

The hypothalamus is afferently connected with other parts of the central nervous system, primarily with the spinal cord, medulla oblongata, and midbrain, thalamus, basal ganglia (subcortical formations located in the white matter of the cerebral hemispheres), the hypocampus (the central structure of the limbic system), separate fields of the cerebral cortex and others. Thanks to this, information from the whole organism enters the hypothalamus; signals from extero- and interoreceptors that enter the central nervous system through the hypothalamus are transmitted by the endocrine glands.

Thus, the neurosecretory cells of the hypothalamus transform afferent nerve stimuli into humoral factors with physiological activity (in particular, hormones in releasing).

The pituitary gland as a regulator of biological processes

The pituitary gland receives signals that notify about everything that happens in the body, but has no direct connection with the external environment. But in order for the vital activity of the organism not to be constantly disturbed by the factors of the external environment, the organism must adapt to the changing external conditions. The body learns about external influences by receiving information from the senses, transmitting it to the central nervous system.

Fulfilling the role of the supreme endocrine gland, the pituitary gland itself is controlled by the central nervous system and, in particular, by the hypothalamus. This supreme vegetative center is engaged in the constant coordination and regulation of the activity of various parts of the brain and all internal organs.

Remark 2

The existence of the whole organism, the constancy of its internal environment is controlled by the hypothalamus: the exchange of proteins, carbohydrates, fats and mineral salts, the amount of water in the tissues, vascular tone, heart rate, body temperature, etc.

A single neuroendocrine regulatory system in the body is formed as a result of the combination at the hypothalamus level of most of the humoral and neural pathways of regulation.

Axons from neurons located in the cerebral cortex and subcortical ganglia approach the cells of the hypothalamus. They secrete neurotransmitters that both activate the secretory activity of the hypothalamus and inhibit it. Nerve impulses coming from the brain, under the influence of the hypothalamus, are converted into endocrine stimuli, which, depending on the humoral signals coming to the hypothalamus from the glands and tissues, are amplified or weakened

The hypothalamus of the pituitary gland is guided by both the nerve connections and the blood vessel system. The blood entering the anterior lobe of the pituitary gland necessarily passes through the median elevation of the hypothalamus, where it is enriched with hypothalamic neurohormones.

Remark 3

Neurohormones are peptide in nature and are parts of protein molecules.

In our time, identified seven neurohormones - liberins ("liberators"), stimulating the synthesis of tropic hormones in the pituitary gland. And three neurohormones, on the contrary, inhibit their production - melanostatin, prolactostatin and somatostatin.

Vasopressin and oxytocin are also neurohormones. Oxytocin stimulates the contraction of the smooth muscles of the uterus during childbirth, the production of milk by the mammary glands. With the active participation of vasopressin, the transport of water and salts through cell membranes is regulated, the lumen of the vessels decreases (blood pressure rises). For its ability to retain water in the body, this hormone is often called antidiuretic hormone (ADH). The main point of application of ADH is the renal tubules, where, under its influence, the reabsorption of water into the blood from the primary urine is stimulated.

The nerve cells of the hypothalamic nuclei produce neurohormones, and then, with their own axons, transport them to the posterior lobe of the pituitary gland, and from here these hormones are able to enter the bloodstream, causing a complex effect on the body's systems.

However, the pituitary and hypothalamus not only send orders through hormones, but they themselves are able to accurately analyze the signals that come from the peripheral endocrine glands. The endocrine system acts on the principle of feedback. If the endocrine gland produces an excess of hormones, then the release of a specific hormone by the pituitary gland slows down, and if the hormone is not produced enough, then the production of the corresponding tropic hormone of the pituitary gland increases.

Remark 4

In the process of evolutionary development, the mechanism of interaction between hypothalamic hormones, pituitary hormones and endocrine glands has been worked out quite reliably. But if at least one link of this complex chain malfunctions, there will immediately be a violation of the ratios (quantitative and qualitative) in the entire system, carrying various endocrine diseases.

CHAPTER 1. INTERACTION OF NERVOUS AND ENDOCRINE SYSTEM

The human body consists of cells that combine into tissues and systems - all this as a whole is a single super-system of the body. The myriads of cellular elements would not be able to work as a whole if the body did not have a complex regulation mechanism. The nervous system and the endocrine gland system play a special role in regulation. The nature of the processes taking place in the central nervous system is largely determined by the state of endocrine regulation. So androgens and estrogens form the sexual instinct, many behavioral reactions. It is obvious that neurons, just like other cells in our body, are under the control of the humoral regulatory system. The nervous system, evolutionarily later, has both governing and subordinate connections with the endocrine system. These two regulatory systems complement each other, form a functionally single mechanism, which ensures high efficiency of neurohumoral regulation, puts it at the head of the systems that coordinate all vital processes in a multicellular organism. The regulation of the constancy of the internal environment of the body, taking place according to the principle of feedback, is very effective for maintaining homeostasis, but it cannot fulfill all the tasks of adaptation of the body. For example, the adrenal cortex produces steroid hormones in response to hunger, illness, emotional arousal, etc. So that the endocrine system can "respond" to light, sounds, smells, emotions, etc. there must be a connection between the endocrine glands and the nervous system.

1.1 Summary of the system

The autonomic nervous system permeates our entire body like the thinnest spider web. It has two branches: excitation and inhibition. The sympathetic nervous system is the excitatory part, it puts us in a state of readiness to face a challenge or danger. Nerve endings secrete mediators that stimulate the adrenal glands to release strong hormones - adrenaline and norepinephrine. They in turn increase the heart rate and respiration rate, and act on the digestive process by secreting acid in the stomach. In this case, there is a sucking sensation in the stomach. Parasympathetic nerve endings secrete other neurotransmitters that lower the heart rate and respiratory rate. Parasympathetic responses are relaxation and rebalancing.

The endocrine system of the human body combines small in size and different in structure and function of the endocrine glands, which are part of the endocrine system. These are the pituitary gland with its independently functioning anterior and posterior lobes, the gonads, the thyroid and parathyroid glands, the adrenal cortex and medulla, the islet cells of the pancreas and the secretory cells lining the intestinal tract. All together they weigh no more than 100 grams, and the amount of hormones they produce can be calculated in billions of a gram. And, nevertheless, the sphere of influence of hormones is extremely large. They have a direct impact on the growth and development of the body, on all types of metabolism, on puberty. There are no direct anatomical connections between the endocrine glands, but there is an interdependence of the functions of one gland on the others. The endocrine system of a healthy person can be compared to a well-played orchestra, in which each gland confidently and subtly leads its part. And in the role of the conductor is the main supreme endocrine gland - the pituitary gland. The anterior pituitary gland releases six tropic hormones into the blood: somatotropic, adrenocorticotropic, thyroid-stimulating, prolactin, follicle-stimulating and luteinizing - they direct and regulate the activity of other endocrine glands.

1.2 Interaction of the endocrine and nervous system

The pituitary gland can receive signals that signal what is happening in the body, but it has no direct connection with the external environment. Meanwhile, in order for the factors of the external environment not to constantly disturb the vital activity of the organism, the body must adapt to the changing external conditions. The body learns about external influences through the senses, which transmit the information received to the central nervous system. As the supreme gland of the endocrine system, the pituitary gland itself obeys the central nervous system and, in particular, the hypothalamus. This higher vegetative center constantly coordinates, regulates the activity of various parts of the brain, all internal organs. Heart rate, blood vessel tone, body temperature, the amount of water in the blood and tissues, the accumulation or consumption of proteins, fats, carbohydrates, mineral salts - in short, the existence of our body, the constancy of its internal environment is controlled by the hypothalamus. Most of the nervous and humoral pathways of regulation converge at the level of the hypothalamus, and due to this, a single neuroendocrine regulatory system is formed in the body. Axons of neurons located in the cerebral cortex and subcortical formations are suitable for the cells of the hypothalamus. These axons secrete various neurotransmitters that have both activating and inhibitory effects on the secretory activity of the hypothalamus. The hypothalamus "converts" the nerve impulses coming from the brain into endocrine stimuli, which can be strengthened or weakened depending on the humoral signals entering the hypothalamus from the glands and tissues subordinate to it.

The hypothalamus directs the pituitary gland using both nerve connections and the blood vessel system. The blood that enters the anterior pituitary gland necessarily passes through the middle elevation of the hypothalamus and is enriched there with hypothalamic neurohormones. Neurohormones are substances of a peptide nature, which are parts of protein molecules. To date, seven neurohormones have been discovered, the so-called liberins (that is, liberators), which stimulate the synthesis of tropic hormones in the pituitary gland. And three neurohormones - prolactostatin, melanostatin and somatostatin - on the contrary, inhibit their production. Neurohormones also include vasopressin and oxytocin. Oxytocin stimulates the contraction of the smooth muscles of the uterus during childbirth, the production of milk by the mammary glands. Vasopressin is actively involved in the regulation of the transport of water and salts through cell membranes; under its influence, the lumen of blood vessels decreases and, therefore, blood pressure increases. Because this hormone has the ability to retain water in the body, it is often called antidiuretic hormone (ADH). The main point of ADH application is the renal tubules, where it stimulates the reabsorption of water from primary urine into the blood. Nerve cells of the hypothalamic nuclei produce neurohormones, and then transport them to the posterior lobe of the pituitary gland along their own axons (nerve processes), and from here these hormones enter the bloodstream, exerting a complex effect on the body systems.

The pathways formed in the pituitary gland not only regulate the activity of the subordinate glands, but also perform independent endocrine functions. For example, prolactin has a lactogenic effect, and also inhibits the processes of cell differentiation, increases the sensitivity of the gonads to gonadotropins, and stimulates the parental instinct. Corticotropin is not only a stimulant of sterogenesis, but also an activator of lipolysis in adipose tissue, as well as an important participant in the process of converting short-term memory into long-term memory in the brain. Growth hormone can stimulate the activity of the immune system, the metabolism of lipids, sugars, etc. Also, some hormones of the hypothalamus and pituitary gland can be formed not only in these tissues. For example, somatostatin (a hypothalamic hormone that inhibits the formation and secretion of growth hormone) is also found in the pancreas, where it suppresses the secretion of insulin and glucagon. Some substances work in both systems; they can be both hormones (i.e. products of the endocrine glands) and mediators (products of certain neurons). This dual role is played by norepinephrine, somatostatin, vasopressin and oxytocin, as well as diffuse gut nervous system transmitters such as cholecystokinin and vasoactive intestinal polypeptide.

However, one should not think that the hypothalamus and pituitary gland only give orders, releasing the "leading" hormones along the chain. They themselves sensitively analyze the signals coming from the periphery, from the endocrine glands. The activity of the endocrine system is carried out on the basis of a universal feedback principle. An excess of hormones of a particular endocrine gland inhibits the release of a specific hormone from the pituitary gland, which is responsible for the work of this gland, and a deficiency prompts the pituitary gland to increase the production of the corresponding triple hormone. The mechanism of interaction between the neurohormones of the hypothalamus, the triple hormones of the pituitary gland and the hormones of the peripheral endocrine glands in a healthy organism has been worked out by long evolutionary development and is very reliable. However, a failure in one link of this complex chain is enough for a violation of quantitative and sometimes qualitative relationships in the whole system to occur, entailing various endocrine diseases.

CHAPTER 2. BASIC TALAMUS FUNCTIONS

2.1 Brief Anatomy

The bulk of the diencephalon (20 g) is the thalamus. The paired organ is ovoid, the anterior part of which is pointed (anterior tubercle), and the posterior expanded one (pillow) hangs over the geniculate bodies. The left and right thalamuses are connected by an interthalamic adhesion. The gray matter of the thalamus is divided by plates of white matter into anterior, medial, and lateral parts. Speaking of the thalamus, they also include the metathalamus (geniculate bodies), which belongs to the thalamic region. The thalamus is most developed in humans. Thalamus (thalamus), the visual hillock, is a nuclear complex in which processing and integration of almost all signals going to the cerebral cortex from the spinal cord, midbrain, cerebellum, basal ganglia of the brain takes place.